JP2567177Y2 - Hot wire detector - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hot-wire detector.

[0002]

2. Description of the Related Art A hot-wire detector of this kind detects a weak heat ray generated from the human body and performs notification control. Since the amplification factor of the amplifier circuit is extremely high, extraneous radio noise and the like are generated. Malfunctions were likely to occur due to interference by the

[0003] Therefore, in such an inner unit block 100 of the hot-wire detector, as shown in FIG.
1, a surplus portion of the conductive foil 101a on the component surface C side (to which the pyroelectric element 102 and the like are attached) is used as a ground pattern, and the amplifier circuit portion 103 is directly mounted on the pattern 101b on the solder surface S side. The amplifier circuit 103 is covered with a conductive shield case 104 from above, and the signal line 105 led out from the solder surface S side is
Conductive shield case 1 through feedthrough capacitor 106
04 to the outside,
The conductive shield case 104 and the ground pattern 101a of the circuit board 101 enclose and amplify the amplifying circuit section 103 so as to eliminate disturbance due to external radio noise. (See the perspective view of FIG. 5). The circuit board 10
The jumper wire J attached to the connector 1 connects the ground pattern on the component surface C and the ground pattern 101b 'on the solder surface S.

However, in the internal unit block 100 having such a conventional structure, the feedthrough capacitor 106 fixed to the conductive shield case 104 and the circuit board 101 are connected in advance by the lead wire 105, and thereafter, the circuit board 101 is connected.
The conductive shield case 104 must be attached to the device, and the number of components of the lead wire 105 increases, and the workability of the wiring process is deteriorated.

[0005]

[Problems to be Solved by the Invention] The present invention proposed in view of the above circumstances has a simple inner unit block structure excluding the lead wires inside the conductive shield case, and thereby,
It is an object of the present invention to provide a hot-wire detector with improved manufacturability.

[0006]

In order to achieve the above object, the present invention proposes an amplifier circuit section on a conductive foil on a solder surface side of a circuit board in which an earth pattern is formed by a conductive foil on a component side. A hot wire detector with a built-in internal block structure that mounts and covers the solder side including this amplifier circuit part with a conductive shield case, and draws out the derived signal lines from the conductive shield case to the outside through a through capacitor. In the above, the eyelet is inserted into the hole formed in the circuit board and press-fitted to secure conduction between the conductive foils on both sides of the circuit board, and the eyelet fitted to the conductive shield case is fitted. The lead terminal of the feedthrough capacitor fixed to the through hole provided at the position corresponding to the component is connected to the eyelet tool from above the circuit board integrally with the conductive shield case. Put, it is within the unit block structure for the conductive adhesive.

[0007]

In the present invention, the conductive foil on the solder side of the circuit board and the conductive foil on the component side are electrically connected by the eyelet tool pressed into the hole of the circuit board. The lead terminal of the through capacitor fixed to the through hole provided at a position corresponding to the eyelet tool fitted,
Attach the conductive shield case to the circuit board by inserting it into the eyelet of the circuit board from above the circuit board integrally with the conductive shield case, and then conductively bond the lead terminals of the feedthrough capacitor to the eyelet. In this case, the feedthrough capacitor can be connected to the pattern on the solder side. This eliminates the need for connecting the conductive foil on the solder side and the feedthrough capacitor with a lead wire, thereby improving the manufacturability.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of an inner unit block 1 of a hot-wire detector according to the present invention.
Reference numeral 10 denotes a component on which a pyroelectric element F or the like is attached on the component surface C side and an amplifying circuit portion AM on the solder surface S side pattern 10b.
A circuit board to which P is directly attached, 11 is a conductive shield case for shielding the amplifier circuit section AMP from external noise, 1
2 ··· The circuit board 1 via the conductive shield case 11
A feed-through capacitor for signal transmission between 0 and the outside, and 13 denotes a ground wire. The ground pattern 10a on the component surface C side and the conductive shield case 11 wrap the amplification circuit unit AMP to provide external radio noise. It is made to shield from.

As shown in the partially enlarged view of the circuit board 10, the eyelet H is fitted into the hole 10c and the component surface C is formed.
The pattern 10a on the side and the pattern 10b on the solder surface S are conducted.

This eyelet tool H has conductivity, and as shown in FIG.
The eyelet H is inserted into the solder surface S from the solder surface S, and the eyelet H is pushed out from the component surface C by a special punch P and fixed. Therefore, the pattern 10a on the component surface C side to which the eyelet H is fitted and the pattern 10a on the solder surface S side
b is in a conductive state, so that if the lead terminal 12a of the feedthrough capacitor 12 is inserted into the eyelet tool H and bonded from the component surface C side with the solder SL, the feedthrough capacitor 12 is eventually connected to the pattern 10b on the solder surface S side. This eliminates the need for connecting the feedthrough capacitor 12 and the pattern on the solder surface S with a lead wire as in the related art. Further, in such an inner unit block 1, the height of the conductive shield case 11 can be reduced, so that a thin structure can be realized.

FIG. 3 shows the procedure for assembling the inner unit block 1 of the hot-wire detector according to the present invention. The through-capacitors 12... And the lead wires 13 are previously soldered to the conductive shield case 11. On the other hand, various components including the pyroelectric element F are mounted on the component surface C side of the circuit board 10, and the amplifying circuit portion AMP is mounted on the solder surface S side pattern 10b.
And the eyelet H is attached, and the conductive shield case 11 is attached to the mounting hole 10 d of the circuit board 10.
10d, and the conductive shield case 11 and the circuit board 10 are combined so that the lead terminals 12a... And the lead wires 13 of each feedthrough capacitor 12 are inserted into the corresponding eyelets H. The lead terminals 12a and lead wires 13 of the feedthrough capacitor 12 and the eyelet H may be solder-bonded from the component surface C side, and furthermore, the conductive shield case 11 and the pattern 10a of the circuit board 10 may be solder-bonded. It can be seen that the improvement is remarkable.

In the present invention, the continuity of the pattern between the component surface C and the solder surface S is ensured by press-fitting the eyelet H onto the circuit board 10, so that the through-hole plating is performed on the double-sided printed circuit board. The cost can be reduced as compared with the case of performing the above. The reliability of the wiring process can be further improved by soldering the eyelet H and the pattern on the component surface C side or the solder surface S side.

[0013]

As can be understood from the above description, according to the hot-wire detector of the present invention, the through-capacitor fixed to the through-hole provided at the position corresponding to the eyelet of the conductive shield case is provided. The lead terminal is integrated with the conductive shield case and inserted into the eyelet tool pressed and fitted directly onto the circuit board from above the circuit board, and is electrically conductively bonded, thereby connecting the feedthrough capacitor and the circuit board. Because of the block structure, another lead wire for connecting the feedthrough capacitor and the circuit board is not required, and the number of components can be reduced and manufacturability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an inner unit block structure of a hot-wire detector according to the present invention.

FIG. 2 is an explanatory diagram of an attaching procedure of an eyelet tool.

FIG. 3 is an explanatory view of an assembling procedure of an inner unit block structure of the hot-wire detector shown in FIG.

FIG. 4 is a cross-sectional view showing an inner unit block structure of a conventional hot-wire detector.

FIG. 5 is an explanatory diagram showing an appearance of an inner unit block of the hot-wire detector shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inner block of a hot-wire detector 10 ... Circuit board 10a ... Conductive foil (pattern) 10b ... Conductive foil (pattern) 10c ... Hole 11 ... Conductive shield case 12: Through capacitor 12a: Lead terminal of through capacitor AMP: Amplifier circuit H: Eyelet tool C: Component surface S: Solder surface

Claims (1)

(57) [Scope of request for utility model registration] An amplifying circuit portion is mounted on a conductive foil on a solder surface side of a circuit board on which an earth pattern is formed by a conductive foil on a component surface side, and the solder surface including the amplifying circuit portion is covered by a conductive shield case. In a hot-wire detector that has an inner unit block structure that covers and draws out the derived signal lines from the conductive shield case through a conductive capacitor, an eyelet is inserted into the hole formed in the circuit board and pressed. By fitting, the conduction of the conductive foil on both sides of the circuit board is ensured, and a through-capacitor fixed to a through-hole provided at a position corresponding to the fitted eyelet of the conductive shield case. A hot wire detector having an inner unit block structure in which a lead terminal is inserted into the eyelet from above the circuit board integrally with the conductive shield case, and the conductive terminal is adhered.